A charge fired across a uniform field (× = into the page) feels a force F = qvB that is always sideways — so it curves into a circle of radius r = mv/(qB). The force only ever turns the particle: its speed never changes.
Magnetic force F = qvB
1.60 × 10-14 N
curving anticlockwise (positive charge)
Radius r
5.69 × 10-5 m
Period T
3.58 × 10-10 s
Speed constant — set by you, unchanged by B
1.00 × 106 m/s
Charge |q|1.6 × 10-19 C
Speed v1.0 × 106 m/s
Field B0.10 T
Mass1 me
Electron me = 9.11 × 10-31 kg · proton ≈ 1836 me · e = 1.60 × 10-19 C